THE MAINSTREAM MATERIAL FOR HEAT DISSIPATION SOLUTIONS

Graphite sheet is a better thermal conductivity material than metals such as copper and aluminum. The main reason is that graphite sheet has a special hexagonal planar network structure, which can evenly distribute heat on a two-dimensional plane and effectively transfer it. In the horizontal direction, the thermal conductivity of graphite sheet is 300 to 1900 W/mk, while the thermal conductivity of copper and aluminum is about 200 to 400 W/mk. In the vertical direction, the thermal conductivity of graphite film is only 5-20W/mk. Therefore, graphite sheet has good horizontal thermal conductivity and vertical thermal resistance. At the same time, the specific heat capacity of graphite sheet is equivalent to that of aluminum, about twice that of copper, which means that after absorbing the same amount of heat, the temperature of graphite will rise only half of that of copper. In addition, the density of graphite sheet is only 0.7~2.1g/cm3, which is lower than 8.96g/cm3 of copper and 2.7g/cm3 of aluminum, so it can be lightweight and can smoothly adhere to any flat and curved surfaces.

Based on the performance advantages of high thermal conductivity, high specific heat capacity and low density, graphite sheet has been used in consumer electronics in batches since 2009, and has been widely used in smart phones in 2011. It has now replaced traditional metals and has become the mainstream heat dissipation material in the consumer electronics field. 

Synthetic graphite film is mainly used in smart phones, and the amount depends on the performance and requirements of the phone, about 3~6 pieces. The parts used include lens, CPU, OLED display, WiFi antenna, wireless charging and battery. Among them, the CPU has the highest performance requirements for heat dissipation, followed by wireless charging, followed by the lens and battery, and finally the display and WiFi antenna. At present, the price of high thermal conductivity graphite film is about 0.2~0.3 US dollars per sheet. According to preliminary estimates, the value of graphite film consumed by a single mobile phone is US$1-2. In the future, with more innovative electronic designs of smart phones, the value of stand-alone graphite films is expected to increase further.